/*
 * Copyright (c) 2017 Kotlin Algorithm Club
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package io.uuddlrlrba.ktalgs.graphs.directed.unweighted

import io.uuddlrlrba.ktalgs.datastructures.Queue
import io.uuddlrlrba.ktalgs.graphs.Graph

class DUGraph(public override val V: Int): Graph {
    override var E: Int = 0
    private val adj: Array<Queue<Int>> = Array(V) { Queue<Int>() }
    private val indegree: IntArray = IntArray(V)

    public fun addEdge(from: Int, to: Int) {
        adj[from].add(to)
        indegree[to]++
        E++
    }

    public override fun adjacentVertices(from: Int): Collection<Int> {
        return adj[from]
    }

    public fun outdegree(from: Int): Int {
        return adj[from].size
    }

    public fun indegree(v: Int): Int {
        return indegree[v]
    }
}
